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Topic: Arpeggiator tempo issue (Read 4110 times)

Midi beat clock is exactly the same as midi clock @ 24 pulses per quarter note. You maybe thinking of MTC which is midi time code;MIDI time code (MTC) or MIDI time division, embeds the same timing information as standardSMPTE timecode as a series of small 'quarter-frame' MIDI messages. There is no provision for the user bits in the standard MIDI time code messages, and SysEx messages are used to carry this information instead. The quarter-frame messages are transmitted in a sequence of eight messages, thus a complete timecode value is specified every two frames. If the MIDI data stream is running close to capacity, the MTC data may arrive a little behind schedule which has the effect of introducing a small amount of jitter. In order to avoid this it is ideal to use a completely separate MIDI port for MTC data. Larger full-frame messages, which encapsulate a frame worth of timecode in a single message, are used to locate to a time while timecode is not running.Unlike standard SMPTE timecode, MIDI timecode's quarter-frame and full-frame messages carry a two-bit flag value that identifies the rate of the timecode, specifying it as either:

Apparently wordclock is supposed to be one of the most accurate forms of syncing equipment so im suprised its not implimented on more synths, drum machines etc. But then it wont work on an analogue synth as it only syncs to samples.

I've never had a synth (digital or analog) where external sync kept the internal Arpeggiator locked to the beat of the master machine for more than 1 minute. Most recently I had a MiniNova and and Electribe EMX and Ableton Live. Arps did not stay on beat.

When you hit a note on the Mini, the arp starts looping its pattern at key-down, not quantized to a grid, and it is not corrected for drift, jitter, and other timing differences. It's not snapping the notes to a timecode or grid. It's refererening the tempo, which is set by itself or by incoming MIDI clock signal. (Which is not a code that says 120bpm, they are little blips that have to be listened to for frequency)

The milisecond discrepancies start to add up. After a little while you can drift a full beat away.

A good arp and clock implementation can be pretty tight for a while, but I wouldn't trust it past a few minutes.

If I wanted a pattern on the Minibrute locked to, say, a drum pattern coming out of Ableton Live or a hardware sequencer, I would send the Minibrute a looping MIDI sequence out of Live or the sequencer. It could even sound like a typical arp pattern. Then every note will happen on time compared to the reference and it can't get ahead or behind.

Ultimately, I would probably do it exactly that way (in fact, programming the pattern into my DAW is how I recorded my recent songs that were written using the MiniBrute's arp). However, it would be nice to be able to jam with two arps in sync with each other. Anyway, when I get time I'll see if I can sync them up going via the DAW, or if it still drifts out.

When you hit a note on the Mini, the arp starts looping its pattern at key-down, not quantized to a grid, and it is not corrected for drift, jitter, and other timing differences. It's not snapping the notes to a timecode or grid. It's refererening the tempo, which is set by itself or by incoming MIDI clock signal. (Which is not a code that says 120bpm, they are little blips that have to be listened to for frequency)

The milisecond discrepancies start to add up. After a little while you can drift a full beat away.

I'm fairly sure the MB doesn't do it this way. I believe it's equivalent to a pulse-driven sync input on, say, a modular analog sequencer. It does not start the arpeggiation in time with the keypress, but always on the beat/subdivision of the beat. I think it really does just, for example with an eighth-note arpeggiation, do one step every 12 midi beats. I think any loss of sync would be due to a missed MIDI clock, which is unlikely.

"Unlike MIDI timecode, the MIDI beat clock is tempo-dependent. Clock events are sent at a rate of 24 ppqn (pulses per quarter note). Those pulses are used to maintain a synchronized tempo for synthesizers that have BPM-dependent voices and also for arpeggiator synchronization. It does not transmit any location information (bar number or time code) and so must be used in conjunction with a positional reference (such as timecode) for complete sync."

"Because of limitations in MIDI and synthesizers, devices driven by MIDI beatclock are often subject to clock drift. For this reason, it is a common practice on equipment that supports another clock source such as ADAT or wordclock to use both that source and MIDI beatclock."

Since the MiniBrute relies on the MIDI clock pulses to set tempo externally with no other reference, it is subject to drift. The sequencer or software is telling the MiniBrute: "Hey! 120bpm," not "OK, play the first note.... NOW!"

And the arp is either starting at key press or at a very fine quantized point - I don't feel any delay. I think the arp is fully "freerunning" and to start it on a downbeat, you have to have accurate fingers.

But again, arpeggiators with ext sync were not designed to replace a sequence sent by a sequencer.

I officially owe the MiniBrute an apology. It seems that it does sync to other devices; as I speak, mine is happily following the tempo of an Electribe ER-1 drum machine. It seems the issue lies with the other synth whose arp I was trying to syn up to the Brute's. I don't know if the original poster ever resolved his/her problem, but mine is solved.

Edit: I should add that I still can't get the tap tempo to work reliably, but that might just be my own ineptness. It isn't really an issue for me, anyway.

The tempo on the Arpeggiator is very erratic, it keeps speeding up! Even regularly using the tap tempo it's impossible to keep in time. Any ideas? i've also experienced it crashing a good few times when using the arpeggiator.

thank you

Hi, I'm using Minibrute with Spark CDM so I connect both devices with midi cable, set the Spark as master device for midi clocking and all midi notes play with arp very nice. So you should just make midi synchronization with your device or software you use, other way you always should turn tempo knob

When you hit a note on the Mini, the arp starts looping its pattern at key-down, not quantized to a grid, and it is not corrected for drift, jitter, and other timing differences. It's not snapping the notes to a timecode or grid. It's refererening the tempo, which is set by itself or by incoming MIDI clock signal. (Which is not a code that says 120bpm, they are little blips that have to be listened to for frequency)

The milisecond discrepancies start to add up. After a little while you can drift a full beat away.

I'm fairly sure the MB doesn't do it this way. I believe it's equivalent to a pulse-driven sync input on, say, a modular analog sequencer. It does not start the arpeggiation in time with the keypress, but always on the beat/subdivision of the beat. I think it really does just, for example with an eighth-note arpeggiation, do one step every 12 midi beats. I think any loss of sync would be due to a missed MIDI clock, which is unlikely.

You totally right clock messages are used as trig. As long as clock messages are not lost, sync will be perfect. I tested it for more than a week long and it was still synced.